Time and current limit relay.



A( S. GUBITT.

TIME AND CURRENT LIMIT RELAY.

APPLIOATION FILED OUT. 15, 1909.

1,019,425. Patented Mar. 5,1912.

2 SHEETS-SHEET 1.

WITNEssEj: INVENTUR 2 ARBH-iEaALD iEuaiTT W2 EYW M ATTY A. S. GUBITT.

TIME AND GURRENT LIMIT RELAY.

APPLICATION FILED OCT. 15, 1909.

Patented M21115, 1912.

2 SHEETS-SHEET 2.

FIETZL INVENTEIRZ ATTY.

. To all whom it 11mgconcern:

i STAKE-FE OFF E AnoiiIBALn s. CUBITT, OFPITTSI'EIELD', MASSACHUSETTS, ASSIGNOR TO-G-ENERAII v ELECTRIC COMPANY, A conromrronor NEW YORK.

' TI AND CURRENTLIMIT RELAY,

S. CUBITT,

vented certain new 'and useful Imp-rovemen-ts in-Time. and Current Limit Relays,

of which 'thekfollowing is a specification.

This invention relates to the operation of electrically controlled. switches and partic- 'ularly to the operation of a plurality of such switches successively and in a certain order; It 1's 'esp e'c1ally usefulin connection 'with ,systemsof electric 'motor control in which 'the'supply of current-is increased step by step by meal 5 of a; plurality. of electrically controlled switches, the successive operation of said switches taking place with a definite interval of time between them. It is now customary toniake this interval depend not onlyupon a mechanical device giying a fixed minimum length to said interval, but also to govern it by, an electromagnet, in circuit with-the motor so that the operation of the next switch will not occur until the counterelectromotive force of thc motor cuts down the impressed "current to a definite-value.

iIn'my pending application filed May 7, 1908, Serial Number 4313 52, I have shown such a system in which there are two actuating .wires controlled by-a relay mechanism so that they are cut into circuit:alte1'-nately..

each wire controlling alternate switches; The present application has reference to a relay mechanism' for such a two'wire notching systemf? in which a mechanical ti1ne-limitingde\-'ice giving adefinite minimum time interval"isxconibined with thecnrrent c011 in series wlth the motor and giving a. variable time 1nterval'. The mechanical time-limiting element I prefer to use is a flywheel, which-isset rotating by either of the relay solenoids'when energized ina di; rection opposite to that in which it is biased by aspiral s ring, )Vhen theenergy imparted to it" y therelay. is expended the s rin returns it to' a" normal position, and the time which is required to effect .t-his operation is the minimum intervalbetween the successiveclosings of the switches.v

In the accompanying drawings, Figure-1 1s. a front elevation of my improved'relay; F1g.'2; 1sjavs1de elevation, partly in section,

Specification of Letters ra tent. Application filed October 15, 1909." Se'ria1 No. 522,799.

' Patente Mai.'5;,1912.

shbling the relay iinerg ized; Figie as.

side elevation, showing'the'position of the.55 parts when therelay is energized; and Fig. 4 1s a perspective. view of the current-coil armature and one of the relay-switch arms.

To asuitable panel 1 oflinsulating material is secured a two-armed. bracket-2 is connecte'dto the common supply wire 9,

-'60 which supports the two relay coils; 3, 4.

their other teifminals being respectively. connected with one of a; pair of switch contacts 10, 11, each located on the opposite side of the panel from that where its coil is' placed.

Thefother contacts of each pair are =con-'. nected respectively to the actuating wires- 12,

13 running tothe motor-controlling switch'es. i I

Near the top of the panel 1' is secured a bracket 1% which supports the current coil 15. Projecting from .said bracket 14; are

pa rallel arms 16 between which is pivotedan armature 17, which i's blased away from'the coil by a spring 1.8 attached to the bracket 11+ and to :1 lug 19 extending. beyond the pivot of said armature. The lower ends of the arms .16 are connected by a pin 20 on which are loosely pivoted two switch-arms 21, 22. Each arm hasa strip 2%ofinsnlat ing material secured to oneside of it.'c arrying metallic pins 24, each'of which is.

adapted to enter between and connect the contacts 11 or'lO as the casem'ay-be, thus: closing the circuit of the-relay coil connectedthereto. i 1

The switch-arn'is 21, 22 drop and. cldseby gravity, but they are opened by the respective relay coils 3,4. A bracket 26 projects from the panel 1 near the-upper end of each rod 7 and serves as a fulcrum ioi' a crank arm 27 to which said rod is piroted. An arn r28 extends from the'hubof said crank and'carries at'its upper-end a roller 99 which lies beneath and-'in' contact-with the ,arlna ture 17 and the. adjacent-switch-arm2101* 22; said arms beingflocatcd on each side of the armature in'proxilmity 'there'to. A

30 is looselypiyoted onthe pin 20 between "the switch-arms, and is-biased upward by a' ing'downwardly from the armature 17. -At

the free end of the armature-is a lip 34 adapted to engage beneath lugs 35 extending. laterally from the adjacent free ends of 5 the switch-arms 21,22.

Between the cranks 27 is rotatably mount} ed' a flywheel 36, preferably journalcd on the. common shaft of said cranks, but free to rotate thereon.- Aspiral sprmg 34 1s coiled within said flywheel, havmg one end attached to said wheel and the other to one of the brackets 26. 'A radial ang'ula rly-ad-v justable lever -38 provided withtwostuds 39 between which said spring passes, en-

1 5 ables the effective length of said: spring to' be varied at will. From each side of the rim of the-flywheel projects a pin40 with which engages-an actuator 41 extending from the .hub of thev adjacent crank. A

- radial lug 42 projects from the rim of the Wheel and is adapted to trip the latch 30.

The operation is as followsz'In accordance with the disclosure in my aforesaid pend-1 ing application, the relay coils 3, 4 are alternately energized. The lifting of 'a core 8 turns the crank. 27 to which it is connected,

and throws over the arm 28,'which lifts the corresponding switch arm and'removes the contact pin 24!. 01-25 from its correspomling 0 contacts Her 10, opening the clrcultofthe other relay coil. The arm 28 also lifts the armature l.7, bringing'lt near enough to the. current 0011- 15 to be attracted and held thereby. The energizing of the relaycoil is only momentary, the core, crank and arm returning to their normal POSltlOllS very quickly. Inasmuch as theprrmature and the switch-arm are pivoted zit-"different points,

switch-arm, the other not being engaged by. the lip on the armature in its normal posi-.

tion. The turning of the crank by the core 8 also throws up the actuator 41, extending from said crank. This, by reason of its engagement with the pin 40, imparts a rotary movement to the flywheel 36, which turns over until its n'l'omentum is checked by the increasing tension of the spring .37. This turning of-the-wheel removes thev lug 4E2 from enga e-rnenh-with' the spring latch 30, allowing sa d latch to rise so that its shoulder 32 will engage the tongue 33 on the armature and lock the armature in its raised position." The switch is thus kept open not v only-by:the.;attraction of the current coil but also, by; the mechanical lock, and cannot clo 'n the current in said coil isreduced Ltd-a ertain value and the lock-is tripped motor-controlling also. So long as the current persists or the lock remains in service, the switch will be held open. The lock will be tripped when the flywheel makes its return rotation,urged by the spiral spring, and the lug 42 strikes the end of the latch and carries it down to the position shown in Fig. 2. The tension of the spiral spring 37 is greater than that ot' the spring- 2-31, so that the latter cannot exert any rebound ng effect on the wheel.

During the time that the switch is open, the

other relay cannot be energized, as, it is in circuit with said switch. The length of this time interval, depends upon two factors, one being the time it takes the flywheel to turn over'and return, the other being the" subsidence of the current energizing the current coil. The first is a predetermined interval which insures a certain minimum delaybetween the successive actuation of the switches. The second. may cause a longer delay now and then,- owing to varying conditions of operation. In either case, tlie invention provides fora gradual acceleration of the motor by the automatic and alternate operation of the two relay coils.

lVhatI claim as new and desire to secure by Letters Patent-of the United States, is:

1. In an electric switch, a switch member, an electromagnet for operating the same, a

flywheel for controllingdhe operation of said switch member biased to rotate in one direction, and meansfor moving said wheel against its bias upon the cnergization of said magnet.

2 In an electric switch, the combination with a pivoted arm for opening said switch, of a fiy-wheel biased to rotate in one direction, and an actuator moving. with said arm and acting to turn said wheel in the opposite direction.

3. In an electric switch, the combination with a movable. switch-arm, of a pivoted arm for opening said switch, a flywheel cooperatingwith said switch-arm and biased to turn in a direction to close said switch, and means for moving said pivoted arm and simultaneously turning said wheel in the opposite direction; j

.1-. In an electric switch, the combination with a movableswitch-arm, of a crank having an arm on its hub for opening said switch, a flywheel biased to turn in one direction, means whereby said wheel effectsthe closing of said switch, and an actuator on said hub for turning said wheel in the opposite direction when said switch is opened.

5. In an elcctricswitch, the combination with a movable switch-arm, of a crank hav-,

ing an arm on its hub for opening said switch, 'a lock for holding said switch open, a flywheel biased to turn in one direct-ion,a

lug on said wheel-to trip said lock, and-ffia'n actuatfi on said hub for'rotating said wheel in. the opposite direction when said switch is opened.

6. In an electric switch, the combination with a movable switch-arm, of an electromagnet, a pivoted armature therefor adjacent to said switch-arm and adapted to engage therewith when'said arm is opened, a crank having an arm for lifting both the 7 switch-arm and the armature, a lock for engaging said armature, a flywheel biased to rotate in one direction, a lug on said wheel to trip said lock, and an actuator on said hub for giving said wheel a rotation in the opposite direction when said switch is opened.

7. The combination with two relay coils adapted to operate alternately, of a switcharm actuated by each coil and controlling the circuit of the other coil, a flywheel biased to rotate in one direction and close said switch-arms, and means whereby each coil can impart to said wheel a rotation in the opposite direction when said coil opens its switch-ar1n.

8. In a time and current relay, the combination with two relay coils adapted to operate alternately, of a switch-arm actuated by each coil and controlling the circuit of the other coil, a current coil adjacent to said relay coils, an armature therefor adapted to engage with and hold each switch arm when open, a locl .for said armature, a flywheel biased to rotate in a direction to trip said lock, and means whereby each coil can impart to said wheel a rotation in the opposite direction when said coil opens its switcharm.

nation with two relay coils, of a single current coil, an armature therefor having a lip, two independent switch-arms adjacent to said armature but pivoted at a different point and having lugs adapted to be en gaged by said lip, and means whereby each coil can lift said armature and its respective switch-arm to open the circuit of the other coil.

10. In a time and current relay, the combination with two relay coils, of a single current coil, an armature therefor having a lip, two independent switch-arms adjacent to said armaturebut pivoted at a different point and having lugs adapted to be engaged by said lip, means whereby each relay coil can lift said armature and its respective switch-arm to open the circuit of the other coil, a mechanical lock for holding said armature and arm raised, a flywheel biased to rotate in a direction to trip said lock, and actuators respectively moved by said coils to give said wheel a rotation in an opposite direction simultaneously with the lifting of said armature.

In witness whereof, I have hereunto set my hand this 14th day of October, 1909.

ARCHIBALD -S. CUBITT.

\Vitnesses:

HELEN ORFORD,

BENJAMIN B. HULL.

9. In a time and current relay, the combi- I 

